A segulah for zera kayama is for the both of them man and wife before relations to say parashat Uv'rashei chad'sheikhem (Num. 28:11-15). Also when the baby is sick, God forbid, they should also both man and wife say parashat Uvrashei chadsheikhem.

Because M'ARoT (luminaries, Gen. 1) is chasser (missing) the WAW which is the vitality of all things. Similarly KaLoT Moshe (Moshe finished) is chasser WAW as well (Z. Waychi 236; and see Z. Pinchas 254). All this is the secret of the moon's blemish, from there is drawn the aspect of M'ART chasser WAW which is the outbreak of diphtheria in children, God forbid (v. Zohar Ber. 19, 33, 34).

For WAW is the vitality of every thing (v. Zohar Ber. 256), therefore lacking the WAW alludes to lacking its vitality as mentioned, so that's from were is drawn death to small children, God forbid. But on Rosh Chodesh the moon starts to fill up and be repaired as is known, for then the ultimate blemish and lacking has been reached, so then immediately starts the repair and filling. So this is the KaLoT being acrostic for Kapara Lekhol Toledotam (atonement to all their generations), as on Rosh Chodesh their generations are repaired as mentioned, as atonement and forgiveness and sweetening are drawn to all their generatoins of Yisrael, as will be drawn to them good long life, therefore parashat Uvrashei Chadsheikhem is a segulah for children as mentioned.